That is what I was thinking...GoPro Roll Bar mount. Any issues with the spin hanging up on the clamp screw posts? I assume they would stick up rather than down. Another idea would be to use the handle bar mount on a smaller diameter tube then duct tape the whole thing to the spin pole. The camera would be in front of the tack and out of the way. Just worried about the spin getting torn.

The waterproof boxes are pretty smooth, and free of sharp edges. Then again, it doesn't take much. You could mount it under the pole too, and just tape everything up that could snag, which would probably hold the mount better as well.

Either way, tie a safety line off to it.

I've got a small chunk of carbon tube I'm going to tape to the boom and use the handlebar clamp so the camera is behind the boat a bit more. I'm pretty sure I'm going to smack it a few times tacking though.